Pneumatic assembly for a pressure decay tester

ABSTRACT

A pneumatic assembly for a pressure decay tester of printhead integrated circuits includes a pressurized air supply. A pneumatic clamping arrangement is in fluid communication with the pressurized air supply for clamping a carrier for the printhead integrated circuits such that the carrier is in fluid communication with the printhead integrated circuits. A valve arrangement applies a predetermined pressure to the carrier. A sensing arrangement senses a static pressure in the carrier. A control system is in communication with the clamping, valve and sensing arrangements to control operation thereof and to generate a discernible signal representing said static pressure such that a decay in said static pressure can be determined.

FIELD OF INVENTION

This invention relates to the field of printer component testing, ingeneral. More specifically, the invention relates to a leak tester for acarrier for printhead integrated circuits, a method for testingintegrity of a base or carrier for printhead integrated circuits, asafety system for a pressure decay tester for a printhead integratedcircuit carrier, a cradle assembly for a pressure decay leak tester, anda pressure-based tester for testing an integrity of a platform assembly.

CO-PENDING APPLICATIONS

The following applications have been filed by the Applicantsimultaneously with the present application:

12/193,715 12/193,716 12/193,717 12/193,718 12/193,719 12/193,72012/193,721 12/193,722 12/193,723 12/193,724 12/193,725 12/193,72612/193,728 12/193,729 12/193,730 12/193,731 12/193,732 12/193,73312/193,734 12/193,735 12/193,736 12/193,737 12/193,738 12/193,73912/193,740 12/193,741 12/193,742 12/193,743 12/193,745 12/193,74712/193,748 12/193,750 12/193,751 12/193,753

The disclosures of these co-pending applications are incorporated hereinby reference. The above applications have been identified by theirfiling docket number, which will be substituted with the correspondingapplication number, once assigned.

CROSS REFERENCES

The following patents or patent applications filed by the applicant orassignee of the present invention are hereby incorporated bycross-reference.

11/246,687 11/246,718 7,322,681 11/246,686 11/246,703 11/246,69111/246,711 11/246,690 11/246,712 11/246,717 7,401,890 7,401,91011/246,701 11/246,702 11/246,668 11/246,697 11/246,698 11/246,69911/246,675 11/246,674 11/246,667 11/829,957 11/829,960 11/829,96111/829,962 11/829,963 11/829,966 11/829,967 11/829,968 11/829,96911,946,839 11,946,838 11,946,837 11,951,230 12,141,034 12,140,26512,183,003 11/688,863 11/688,864 11/688,865 7,364,265 11/688,86711/688,868 11/688,869 11/688,871 11/688,872 11/688,873 11/741,76612,014,767 12,014,768 12,014,769 12,014,770 12,014,771 12,014,77212,014,773 12,014,774 12,014,775 12,014,776 12,014,777 12,014,77812,014,779 12,014,780 12,014,781 12,014,782 12,014,783 12,014,78412,014,785 12,014,787 12,014,788 12,014,789 12,014,790 12,014,79112,014,792 12,014,793 12,014,794 12,014,796 12,014,798 12,014,80112,014,803 12,014,804 12,014,805 12,014,806 12,014,807 12,049,37112,049,372 12,049,373 12,049,374 12,049,375 12,103,674 12,146,399

BACKGROUND

In order to ensure proper printing operation, it is important to testprinthead integrated circuit prototypes prior to large-scale fabricationof the printhead integrated circuits.

Such testing can be carried out on some form of support assembly, baseor carrier fabricated for testing purposes. In order for the testing tobe accurate and properly indicative of the condition of the printheadassembly, the support assembly must meet minimum standards of integrity.

SUMMARY

According to a first aspect of the invention there is provided a leaktester for a carrier for printhead integrated circuits, said carrierhaving at least one fluid inlet in fluid communication with a pluralityof fluid outlets via discrete fluid paths, the tester comprising:

-   -   a support assembly that includes at least one receptacle shaped        and configured to receive at least one respective carrier;    -   a pressurized fluid supply arranged on the support assembly and        configured to supply pressurized fluid to the fluid inlets, the        pressurized fluid supply incorporating a sealing mechanism        configured to engage the fluid inlets in a sealing manner;    -   a pressure measurement arrangement operatively arranged with        respect to the pressurized fluid supply to measure pressure        applied at the fluid inlets; and    -   a controller operatively connected to the pressure measurement        arrangement and pressurized fluid supply, the controller being        configured to control the fluid supply to charge the carrier        with pressurized fluid until a predetermined pressure is        reached, and to monitor the pressure for a predetermined period        of time.

Thus, this aspect of the invention provides a means for testing theintegrity of a carrier in which printhead integrated circuits is to betested. It will be appreciated that leakage between components of thecarrier are indicated if the pressure monitored by the controller decaysover a period of time.

The receptacles may include locators to locate the carriers in thereceptacles prior to engagement of the sealing mechanisms with the fluidinlets. Each sealing mechanism may include a clamp arrangement forclamping about the fluid inlet.

The controller may include an operator interface arranged on the supportassembly allowing an operator to control the tester. The interface mayinclude indicators to indicate an operational status of the tester to anoperator.

The pressurized fluid supply may include a pneumatic system mounted inthe housing assembly, the pneumatic system including pneumatic circuitsin fluid communication with respective receptacles, the pneumaticcircuits each including a primary pressure regulator for primaryregulation and a secondary pressure regulator for final regulation.

Each pneumatic circuit may include the pressure measurement arrangementin turn including a positive pressure sensor for sensing a systempressure and a number of compound pressure sensors to sense pressure atthe sealing mechanism.

According to a second aspect of the invention there is provided a methodfor testing integrity of a base for printhead integrated circuits, thebase having at least one fluid inlet in fluid communication with aplurality of fluid outlets via discrete fluid paths, said methodcomprising the steps of:

-   -   engaging the, or each, fluid inlet of the base to a fluid supply        in a sealing manner;    -   charging the base with pressurized fluid until a predetermined        pressure is reached; and    -   monitoring the pressure in the base for a predetermined period        of time, wherein a rate of pressure decay is indicative of an        integrity of the base.

The fluid inlet may be engaged to a pneumatic system so that the base ischarged with pressurized gas. The step of sealing may include clampingthe fluid inlet to the fluid supply via a clamping arrangement.

The pressurized gas may be subjected to primary and secondary regulationsubstantially to neutralize the effect of supply pressure variations.The step of monitoring may include the step of sensing the pressure inthe pneumatic circuit and generating a signal representing a valueassociated with the pressure.

The step of monitoring may include indicating data associated with saidvalue to an operator.

According to a third aspect of the invention there is provided apneumatic assembly for a pressure decay tester of printhead integratedcircuits, the assembly comprising

-   -   a pressurized gas supply;    -   a pneumatic clamping arrangement in fluid communication with the        pressurized gas supply for clamping a carrier for the printhead        integrated circuits such that the carrier is in fluid        communication with the printhead integrated circuits;    -   a valve arrangement to apply a predetermined pressure to the        carrier;    -   a sensing arrangement to sense a static pressure in the carrier;        and    -   a control system in communication with the clamping, valve and        sensing arrangements to control operation thereof and to        generate a discernible signal representing said static pressure        such that a decay in said static pressure can be determined.

The pneumatic clamping arrangement may include a support on which thecarrier is supported. The clamping arrangement may be configured sothat, when actuated, the carrier is urged against the support.

The support may define gas supply openings in which gas inlet spouts ofthe carrier are received in use.

The valve arrangement may include an gas supply isolation valveoperatively connected to the control system to isolate the gas supplyopenings from the pressurized gas supply during determination of saidstatic pressure.

The sensing arrangement may include a pressure transmitter operativelyconnected to the control system to communicate pressure values upstreamof the isolation valve to the control system.

The clamping arrangement may include pneumatic spout clamps positionedin the support to clamp the spouts in position.

The valve arrangement may include spout clamp valves operativelyconnected to the control system to control operation of the spoutclamps.

According to a fourth aspect of the invention there is provided a cradleassembly for a pressure decay leak tester, said assembly operativelyreceiving a printhead integrated circuit carrier having a plurality ofprinting fluid paths defined therein, respective fluid inlets in fluidcommunication with respective fluid paths and a locating formation tofacilitate correct location of the carrier on the tester, the assemblycomprising:

-   -   at least one complementary locating formation for engaging the        locating formation of the carrier;    -   at least one fluid outlet for charging the carrier with fluid        via a respective fluid inlet of the carrier;    -   a clamping device for clamping the carrier to the fluid outlet,        so that the integrity of the fluid paths is observable via        pressure decay testing; and    -   a control system operatively connected to the clamping device        for controlling operation of the clamping device.

The clamping device may include two opposing coplanar clamp halves andsaid complementary location formation is a pair of spigots interposedbetween the clamp halves, so that actuation of the clamping devicedisplaces the halves towards each other to embrace the carrier locatedon said spigots.

The clamping device may include a support plate, the spigots extendingfrom the support plate. The clamp halves may be shaped to engage edgesof the carrier and to urge the carrier against the support plate whenthe halves are displaced towards each other. The clamping device mayinclude one of a pneumatic and a hydraulic actuator.

The clamp halves may each define digit recesses to facilitate manualinsertion and removal of the carrier from the assembly. The controlsystem may be configured to receive a particular signal from the testerand to deactivate the clamping device on receipt of said signal.

According to a fifth aspect of the invention there is provided apressure-based tester for testing integrity of a platform assemblyhaving a pair of assembled platform components fastened together and afluid path extending into both components, the platform assemblysuitable for supporting printhead integrated circuits to be tested, thetester comprising

-   -   a housing assembly;    -   a regulated gas supply arranged in the housing assembly;    -   a retaining mechanism in fluid communication with the gas supply        and configured to retain the platform assembly in fluid        communication with the gas supply during testing of the platform        assembly;    -   a pressure measuring apparatus operatively connected to the gas        supply and configured to generate a signal corresponding to a        pressure value applied to the retaining mechanism; and    -   a control system configured to control operation of the        regulated gas supply and the retaining mechanism and configured        to receive the signal from the pressure measuring apparatus and        to detect decay in the pressure value.

The control system may include a touch panel processing deviceoperatively connected to the regulated gas supply, the retainingmechanism and the pressure measuring apparatus.

The touch panel processing device may be configured to generate agraphic user interface that displays pressure test results as aCartesian plane graph with pressure and time on respective axes. Theretaining mechanism may include a cradle assembly and a clampingmechanism to clamp the platform in the cradle assembly.

The cradle assembly may incorporate a pair of spaced manifolds arrangedon the housing assembly and having outlets capable of engagingrespective fluid paths of the platform assembly. The gas supply mayinclude a pair of gas supply conduits and a pair of manifold isolationvalves for connecting respective manifolds to the gas supply conduits.

The gas supply may include a system isolation valve, the pressuremeasurement apparatus being interposed between the system isolationvalve and the manifold isolation valves.

According to a sixth aspect of the invention there is provided asoftware product for execution by a controller of a leak tester, asdescribed above, said software product enabling the leak tester toperform a method having the steps of:

-   -   engaging the, or each, fluid inlet of the base to a fluid supply        in a sealing manner;    -   charging the base with pressurized fluid until a predetermined        pressure is reached; and    -   monitoring the pressure in the base for a predetermined period        of time, wherein a rate of pressure decay is indicative of an        integrity of the base.

According to a seventh aspect of the invention there is provided amemory incorporating a software product, as described above.

Embodiments of the invention are now described, by way of example, withreference to the accompanying drawings. The following description isintended to illustrate particular embodiments of the invention and topermit a person skilled in the art to put those embodiments of theinvention into effect. Accordingly, the following description is notintended to limit the scope of the preceding paragraphs or the claims inany way.

BRIEF DESCRIPTION OF THE DRAWINGS

In the accompanying drawings:

FIG. 1A shows, in side perspective view, a carrier for printheadintegrated circuits for use with a leak or pressure decay tester, inaccordance with one embodiment of the invention;

FIG. 1B shows a side view of the carrier of FIG. 1A.

FIG. 2 shows a close-up perspective view of a portion of the carriershown in FIG. 1;

FIG. 3 shows a front perspective view of a pressure decay leak tester,in accordance with one embodiment of the invention;

FIG. 4 shows a close-up view of a receptacle or cradle assembly, inaccordance with one embodiment of the invention, of the leak testershown in FIG. 3;

FIG. 5 shows a perspective view of the carrier of FIG. 1 located in thecradle of FIG. 4;

FIG. 6 shows an operator interface of the leak tester of FIG. 3;

FIG. 7 shows a rear view of a housing of the leak tester of FIG. 3 witha service panel removed to reveal inner components;

FIG. 8 shows a section top view from line A-A′ of the open service panelof the leak tester of FIG. 7;

FIG. 9 shows a close-up frontal view of a touch panel controller of theleak tester of FIG. 3;

FIG. 10 shows a rear view of a services panel of the leak tester of FIG.3;

FIG. 11 shows an overview pneumatic circuit diagram for the leak testerof FIG. 3;

FIG. 12 shows an example of a graphic user interface displayed by thetouch panel controller of FIG. 9;

FIG. 13 shows a block diagram of a method of testing the carrier withthe leak tester, in accordance with the invention; and

FIG. 14 shows a detailed pneumatic circuit diagram for the leak testerof FIG. 3.

DETAILED DESCRIPTION

Broadly, the invention provides a means to conduct pressure decaytesting on a carrier 10 shown in FIG. 1. The carrier 10 is an assembly.It is therefore necessary to test the integrity of that assembly priorto carrying out tests on integrated circuits positioned on the assembly.

The carrier 10 generally includes a channel member 18 and a cover member20 which are bonded to each other with an adhesive along a bond line 24(FIG. 2). The members 18 and 20 define a number of ink paths or channelstherethrough. These paths terminate as microscopic fluid outlets 12which are used to supply a printhead integrated circuit (not shown) withprinting fluid in operation.

The carrier 10 also includes a laminate 14, which defines laser ablatedholes aligned with the fluid outlets 12. The laminate 14 is thermallybonded to the channel member 18, as shown, along a bond line 22. Fluidinlets or spouts 11 extend from the cover member 20. Locating or spigotapertures 25 (FIG. 2) discussed in more detail below are defined inrespective ends of the carrier 10.

The purpose of the carrier 10 is to distribute printing fluids from anumber of reservoirs via tortuous ink paths to the printhead integratedcircuits. The printing fluids are fed, under pressure, into the carrier10 via the spouts 11.

Before the printhead integrated circuits can be attached to the laminate14, it is necessary to ensure that the members 18 and 20, as well as thelaminate 14, are properly bonded and attached to prevent leakage ofprinting fluids. For this reason, the integrity of the bond lines 22, 24should be tested or checked. One way of testing is to apply pressurizedfluid to the carrier 10, via the spouts 11, to hold the pressure and totest pressure decay.

FIG. 3 shows one possible embodiment in accordance with the invention ofa pressure decay leak tester 26 for testing the carrier 10. TheInventors have identified pressure decay testing as a suitablemethodology for this purpose. In the embodiment shown, the tester 26includes a housing assembly 42 which has a support assembly or platform30 having a left receptacle or cradle assembly 28.1 and a rightreceptacle or cradle assembly 28.2, each, in accordance with oneembodiment of the invention, for receiving the carrier 10. Each cradleassembly 28 is a retaining mechanism to receive and position the carrier10.

It is to be appreciated that the tester 26 can have any number ofreceptacles or cradle assemblies 28. In the embodiment shown, the twocradle assemblies 28 allow, for example, simultaneous testing of twocarriers 10, or continuous testing of carriers as one carrier can betested whilst another is inserted into an unoccupied cradle assembly andprepared for testing.

The tester 26 also includes a controller or control system that includesa touch panel processing device 36, and an operator interface 32 locatedon the housing 42, as shown. The touch panel controller 36 and interface32 allow an operator or user to control and operate the tester 26. Thetester 26 also includes a number of indicators or gauges 38 to show anoperational status of the tester 26. A barcode scanner or reader 34 isconnected to the controller 36. It reads an identifier or barcode fromthe carrier 10 and communicates associated data to the controller 36.The rationale herefor is explained below.

In addition, the tester 26 also includes an interface, such as a USBinterface, to allow the controller 36 to interface with a computer orother remote monitoring system (not shown).

FIGS. 4 and 5 show a cradle assembly 28 in more detail. In theembodiment shown, the cradle assembly 28 features a sealing, engagementor retaining mechanism 54 in the form of a clamp arrangement or clampingdevice having two opposing coplanar clamp halves 56.1 and 56.2, asshown. The cradle assembly 28 includes locators or locating formationsin the form of a pair of spigots 50 interposed between the clamp halves56. Each spigot 50 is received through a respective spigot opening 25 ofthe carrier 10 to locate the carrier 10 in the assembly 28.

The locating formations or spigots 50 engage the apertures 25 of thecarrier 10, to ensure that the fluid inlets or spouts 11 of the carrier10 are aligned with, and received in, respective fluid supply outlets orspout holes 52 of the cradle 28. The outlets 52 are used to charge thecarrier 10 with pressurized fluid, in use. The clamping device 54includes a support plate 58 with the spigots 50 extending from thesupport plate 58.

Pneumatically operated spout clamps (described in further detail withreference to FIG. 14) are positioned in the support plate 58 to clampthe spouts 11 in an airtight manner.

The clamp halves 56 have opposed bearing edges 57 that are shaped toengage edges of the carrier 10 and to urge said carrier 10 against thesupport plate 58 when the halves 56 are displaced towards each other.The clamp halves 56 each define digit recesses 60 to facilitate manualinsertion and removal of the carrier 10 from the cradle 28.

The clamp halves 56 are connected to the plate 58 with pneumaticactuators 61 on each side of the plate 58. The pneumatic actuators 61form part of a pneumatic circuit (FIG. 14), described in further detailbelow.

FIG. 6 shows a more detailed view of the operator interface 32. Theinterface 32 includes a start button to start a pressure decay test foreach one of the cradles 28. These respective buttons are indicated byreference numerals 62 and 64. Also included is an emergency stop button68, a reset button 70 which resets the tester 26, and a scan button 66which activates the barcode scanner 34. The Inventor has found buttonsmanufactured by Sprecher & Schuh to be suitable for this application.

The emergency stop button 68 is a 40 mm, twist and pull-to-release,non-keyed, heavy duty operating button incorporating a normally closedswitch. The reset button 70 is a flush, momentarily illuminated, bluelens push button having a normally open switch. The start buttons 62 and64 are two flush, momentarily illuminated, green lens push buttonshaving normally open switches. The scan button 66 is similar, but has anamber lens.

A rear portion of the housing assembly 42 of the tester 26 is shown inFIG. 7 with a service panel removed to show the inner workings thereof.The controller 36 and associated pressurized fluid supply components areshown in more detail.

As shown, the tester 26 includes the touch panel controller 36 which hasan integrated processor to process the necessary instructions to controland operate the components of the tester 26. The Inventor has found thatthe Advantech™ PPC-123T touch screen display including an Intel™Pentium™ III processor is suitable for the application. The controller36 uses a PCMCIA data acquisition card 72 coupled with a dedicatedbreakout board 84 to interface the card 72 with precision pressuresensors located in the respective cradles 28. The board 84 typicallyincludes a precision resistor per sensor, i.e. two resistors for theembodiment shown.

It is to be appreciated that trunking 97 is provided to facilitate theconnection of the relevant electrical and/or pneumatic components. Asshown, trunking 97 forms a channel or conduit for electrical andpneumatic wires and lines. Further shown are rail 85 and connectorblocks 87 to facilitate the interconnection of electrical components.

The tester 26 further includes digital input-output modules 86. TheInventor has found three ADAM-4055™ modules manufactured by Advantech™to be suitable for this purpose. These modules 86 include an isolatedconverter to convert RS-232 signals from the controller 36 into isolatedRS-422 or RS-485 signals without having to change the controller'shardware or software. The Inventor has identified Advantech™ modelADAM-4520 as a suitable unit.

The embodiment of the tester 26 shown includes two power supplies topower the different components. Reference numeral 102 refers to a DCpower supply unit which is an AC/DC switching power supply unit with asingle output and remote open sense lead protection features. TheInventor has found the Condor International Plus Series 24V Dc powersupply to be suitable. In addition, reference numeral 94 indicates aprimary switched-mode power supply unit used in the embodiment shown.The Inventor has found the Phoenix Contact 24V DC 2A(MINI-PS-100-240AC/24DC/2) model suitable for this application.

Also included is a safety relay 90, and three solid state relays 88, twoapplied to isolate a pneumatic system of the tester, and the third toallow the controller 36 to activate or deactivate the barcode scanner34. The Inventor has found the Omron™ G92002 relay suitable for thesafety relay 90, and Weiland™ Flare 24V DC terminal relays suitable forthe solid state relays, as shown.

The tester 26 also includes a residual current circuit breaker 96 as asafety feature. The breaker 96 provides over current protection andearth leakage protection. The breaker 96 is generally a single pole unitwith a switched neutral which detects an AC residual current while alsohaving an earth fault indication window with a trip free mechanism. TheInventor has found the Hager™ AD810T residual current circuit breakersuitable for the task.

The barcode scanner 34 is located at the front of the tester 26 so thatan operator can scan a barcode of the carrier 10 prior to inserting thecarrier 10 into the cradle assembly 28. The Inventor has found theIT3900 barcode scanner manufactured by Hand Held Products Inc. to besuitable for this application. Also included are fuses 92 for safetyreasons.

A broad overview of a pneumatic test circuit of the device is shown inFIG. 11. The test circuit has a main pressure inlet 128. A systemisolation valve or main air isolation switch 134 (reference numeral 206in FIG. 14) is positioned downstream of the inlet 128. A main pressuregauge or system pressure indicator 74 (reference numeral 258 in FIG. 14)is positioned downstream of the valve 134. Left and right isolationvalves 252, 254 are connected in parallel to each other downstream ofthe system isolation valve 134.

Left and right spout arrangements 238, 240 are connected to respectiveisolation valves 252, 254 to receive pressurized air when the isolationvalves 252, 254 are opened. Each arrangement 238, 240 has a number ofthe fluid supply outlets 52. Spouts 11 of respective carriers 10 arereceived and clamped in the outlets 52 of respective arrangements 238,240.

Pressure transmitters 248, 250 are connected to respective arrangements238, 240 to transmit pressure values to the controller 36 so thatpressure decay in the carriers 10 can be determined.

The pneumatic circuit is shown in more detail in FIG. 14 and generallyindicated with reference numeral 200. Air is supplied to the circuit viaa manual isolation valve 202. After mist separation at 204, a systemisolation valve 206 controls air supply to the circuit 200.

A take-off line 210 is connected downstream of the isolation valve 206via a two-way connector 208. A right spout clamp arrangement 212 and aright clamp assembly 214 are connected in parallel to the line 210. Aleft spout clamp arrangement 216 and a left clamp assembly 218 are alsoconnected in parallel to the line 210.

The spout clamp arrangements 212, 216 serve to clamp the spouts 52 alsodescribed above with reference to FIG. 4.

Each clamp assembly 214, 218 has two pairs of sleeve and pistonactuators 220, each pair physically represented as 61 in FIG. 4. Theactuators 220 are connected to the line 210 via respective solenoidvalves 222. The valves 222 are connected to the controller 36 so thatclamping of the carriers 10 can be initiated by the controller 36.

Each spout clamp arrangement 212, 216 has five pneumatic spout clamps224, in the respective spouts physically indicated at 52 in FIG. 4. Thespout clamps 224 are connected in parallel to the line 210, viarespective solenoid valves 226 and pressure indicators/switches 228 inseries.

Respective pressure regulators 230 interconnect the line 210 and eachpressure indicator 228. The solenoid valves 226 and the indicators 228are connected to the controller 36 so that pressure supplied to thespout clamps 224 is controlled.

A second take-off line 232 is connected downstream of the connector 208via a two-way connector 234 and a pressure regulator 236. The secondtake-off line 232 supplies pressurized fluid to the left spoutarrangement 238 and the right spout arrangement 240. Each spoutarrangement 238, 240 has a manifold 242 with five solenoid valves 244connected in parallel to the manifold 242. A filtered outlet 246 isconnected to each valve 244 to supply filtered air to the carrier 10 viathe spouts 11.

The pressure transmitters or pressure indicators/switches 248, 250 areconnected in parallel to respective valves 244 of respective spoutarrangements 238, 240 and in series to respective solenoid isolationvalves 252, 254. The switches 248, 250 are connected to the controller36 so that pressure applied at the spouts 11 can be recorded by thecontroller 36. The solenoid isolation valves 252, 254 are operativelyconnected to the controller 36 to facilitate operation of the valves252, 254.

In turn, the isolation valves 252, 254 are connected in parallel to atest pressure indicator/switch 256. Thus, once the carrier 10 has beenpressurized to a predetermined extent via the valves 244 using pressurefeedback values from the pressure indicator 256, the valves 244 can beclosed to the air supply. The indicators 248, 250 are connected to thecontroller 36 and are configured for feeding pressure values back to thecontroller 36 to determine whether, and to what extent, pressure decayis occurring.

A system pressure indicator/switch 258 is connected in series to theindicator 256 and is connected to the controller 36 to monitor systempressure. A pressure regulator 260 is interposed in series between theindicators 256, 258. A further pressure regulator 266 is interposedbetween the indicator 258 and the connector 234.

Return lines 262 are connected together at 264 upstream of the indicator256 and connect to respective spout arrangements 238, 240 via respectivesolenoid isolation valves 252, 254.

It follows that the tester 26 has a pneumatic system and pressuremeasurement arrangement that comprises a number of sensors, valves,filters and regulators. Pressure sensors 74 and 124 (FIG. 7 andrepresented as the system pressure indicator 258 and the test pressureindicator 256 in FIG. 14) are digital compound pressure sensors. Thesensors 74 and 124 are typically configured to measure both positive andvacuum pressure. The Inventor has found SMC ZSE40 digital pressuresensors to be suitable for this purpose.

Pressure regulator 76 (shown physically in FIG. 7 and represented asregulator 266 in FIG. 14) is an SMC IR series pressure regulator forprimary regulation. Pressure regulator 104 (shown physically in FIG. 7and represented as regulator 260 in FIG. 14) is a Fairchild 1000 serieshigh precision pressure regulator for final regulation of the air supplyto the respective cradles 28. Pressure regulators 82 and 98 (shownphysically in FIG. 7 and represented as regulators 230 in FIG. 14) areused on the respective cradles 28, with pressure regulator 80(represented as regulator 236 in FIG. 14) for pilot air pressure. Theseregulators 80, 82 and 98 are SMC AR 20K series regulators having abackflow mechanism to ensure a quick release of air pressure to releasethe carrier 10 from the cradle 28. Pressure sensors 78 and 100 (shownphysically in FIG. 7 and represented as indicators 228 in FIG. 14) areSMC ISE40 digital pressure sensors.

FIG. 8 shows a bottom portion of the panel shown in FIG. 7. Pressuretransmitters 120 (represented as indicators 248, 250 in FIG. 14) are twoGE PTX 1400 transmitters used in the respective cradles 28. Thesetransmitters use an integral electronics system to provide a 2 wire 4 to20 mA output proportional to the applied pressure.

Reference numerals 106, 108, and 110 refer to 3-port solenoid valves(referred to as solenoid valves 252, 254 and 244 in FIG. 14). TheInventor has found the SMC SYJ500 series 3-port, pilot operated solenoidvalve to be suitable. These valves are base mounted 24V DC valves withsurge voltage protection.

Reference numeral 112 indicates 5-port solenoid valves (referred to assolenoid valves 222, 226 in FIG. 14) to control the spout clamps 224.The Inventor has found the SMC SY3160 valves suitable. These valves are24V DC body-ported, cassette type solenoid valves with fittings for a 6mm air pipe.

Air filters 114 and 122 are used to remove any particles from the airbefore charging the carrier 10 with pressurized air. The Inventor hasfound SMC SF series inline air filters to be adequate for this purpose.Also included are mist separators 118 and micro-mist separator 116 toremove moisture from the pneumatic system. The Inventor has found theSMC AFM series mist separator suitable for 118, and the SMC AFD seriesmist separator suitable for 116.

FIG. 9 shows the components of FIG. 7 in front view. Like components areindicated by like reference numerals. Similarly, FIG. 10 shows anoutside view of the components of FIG. 8, with like reference numeralsindicating like components.

As shown, the tester 26 includes a mains AC power isolation switch 132and the main air supply isolation switch 134. A mains power IECconnector 130 is also included, along with a 6 mm main air supplyconnector for connecting a pressurized fluid supply to the pneumaticsystem of the tester 26. An RJ45 connection 127 is also present, toconnect the controller 36 to a remote monitoring system.

The remote monitoring system (not shown) interfaces with the tester 26via the controller 36. The remote monitoring system is able to monitorthe tester 26 to record the operations performed. Of particular use isthat the remote monitoring system can monitor the barcodes of eachcarrier tested, along with the result of the pressure test so performed.For example, each carrier is scanned with the barcode scanner 34 beforeit is tested. The barcode is sent to the remote monitoring system, alongwith the test result.

This remote monitoring prevents inferior carriers from proceeding withsubsequent processing, such as being fitted with printhead circuitry, aseach carrier must typically be identified by its barcode before furtherprocessing thereof can take place.

FIG. 12 shows a graphical user interface (GUI) 138 which is typicallydisplayed on the controller's touch panel display. As shown, the GUI 138comprises two Cartesian graphs 139, one for each cradle 28. The graphs139 indicate a pressure measurement along a Y-axis and time on anX-axis.

In the embodiment shown in FIG. 12, the left graph 139.1 shows a graphfor a carrier 10 which has passed the pressure decay test. The carrier10 is charged with pressurized fluid as described with reference to FIG.14 and the controller 36 monitors the pressure decay over apredetermined period of time through its connection with the indicators248, 250. If there is insignificant pressure decay, as shown by thehorizontal line of graph 139.1, then the integrity of the fluid pathsand laminate of the carrier 10 is confirmed.

Graph 139.2 shows the result of a failed pressure decay test on acarrier. As shown, the pressure in the carrier declines over time, whichindicates that the integrity of the fluid paths or laminate isinsufficient.

The tester 26 also includes a safety system to ensure safe operationthereof and to minimize damage to the carrier 10 and the tester 26, aswell as harm to the operator. It is to be appreciated that the safetysystem is typically implemented via the controller 36.

As such, the controller 36 is linked to a number of regulators, asdescribed above, which include sensors or indicators, as describedearlier, for monitoring air pressure. An incorrect pressure typicallyindicates an undesirable operational status of the tester 26, and thecontroller 36 can deactivate the tester 26 and its components to preventdamage and/or harm.

As such, each cradle 28 may include a sensor which senses a position ofthe clamping mechanism 54 and reports it to the controller 36. If thecarrier 10 is not correctly located in the cradle 28, then thecontroller 36 prevents the clamping mechanism 54 from damaging thecarrier 10.

A person skilled in the art will appreciate that the controller 36 maybe configured to monitor features relating to the operational status ofthe tester 26. This is achieved by processing feedback data receivedfrom the indicators described with reference to FIG. 14. For example,the controller 36 can monitor a condition of the engagement mechanism54, as described above, the fluid pressure applied by the fluid pressureapplication arrangement of the tester 26, a presence of the carrier 10in the cradle 28, etc. In one embodiment, the barcode scanner 34 can beused to verify an authenticity of the carrier 10. For example, asexplained above, the remote monitoring system monitors the respectivecarriers. If a carrier is scanned with the scanner 34, the remotemonitoring system is able to verify whether or not that particularcarrier has passed or cleared all the preceding manufacturing processes.If the carrier has an invalid barcode, the controller 36 will notify theoperator and not test the carrier.

Similarly, the controller 36 is able to monitor an electricity or airsupply to the tester 26 for undesired levels, or the like. Thecontroller 36 is also typically configured so that the operator isrequired to key in an operator identifier for identification purposes,so that a record can be kept of which operator tested which carrier, orthe like.

FIG. 13 shows a diagram for a method, in accordance with one embodimentof the invention, of testing the integrity of the carrier 10 with thetester 26. The blocks in the diagram may indicate steps performed by theoperator or by the controller 36 of the tester 26.

It is to be appreciated that reference to a reference numeralrepresenting a particular method step refers to a respective blockindicated by such reference numeral in the accompanying drawings. Assuch, the method included in the invention is not limited or constrainedto particular method steps referred to in this manner. A skilled personwill understand that further methods are possible under this inventionwhich might exclude some of these steps or include additional steps.

In general, the method commences with the operator scanning the barcodeof the carrier 10 with the scanner 34 of the tester 26, shown at block140. If the scan is successful, the identity of the carrier, asestablished by the barcode, is transmitted to the remote monitoringsystem, as shown at block 142. If the scan is unsuccessful, perhaps dueto a damaged barcode, the carrier 10 is quarantined for laterexamination, as at block 144.

The operator then proceeds to place the carrier 10 in the cradle 28,indicated at block 146. At block 148, the operator presses the startbutton once the carrier 10 is properly loaded. The controller 36 senseswhether or not the carrier 10 is properly located in the cradle 28. Ifthe carrier 10 is properly positioned, the controller 36 engages thecarrier with the clamping mechanism 54, shown at block 150. If thecarrier is not correctly positioned in the cradle, the controller 36will typically notify the operator via the display screen.

Once the carrier 10 is clamped in the cradle 28, the controller 36performs the pressure decay test at 152 by charging the carrier withpressurized air via the fluid supply outlets 52 in the cradle 28. Thepressure sensors, as described above, in communication with theseoutlets 52 enable the controller 36 to monitor the pressure in thecarrier for a predetermined period of time. For example, the controller36 charges the carrier with pressurised air until a predeterminedpressure is reached, whereafter the pressure in the carrier is monitoredby the pressure sensors for, say, 5 seconds. If no appreciable pressuredecay is sensed, the integrity of the carrier is sound.

Once the test is completed, the controller 36 is able to report theresults thereof directly to the remote monitoring system via the RJ45connector 126, as described above, shown at block 154. That data isuploaded to the remote monitoring system at 162. The results are alsoshown to the operator via the display screen of the controller 36. Afterthe test, the controller 36 releases the clamping mechanism 54 at 156 sothat the operator is able to remove the carrier from the cradle 28,shown at block 158. If the carrier passed the test, the operator allowsit proceed to the next step in the manufacturing process, otherwise thecarrier is placed in quarantine for later examination. This is shown inblock 160.

It is to be appreciated that the invention also includes a softwareproduct for execution by the controller 36 of the leak tester 26, asdescribed above. The software product enables the leak tester to performthe functions and relevant method steps described above. The inventioninherently includes a memory, such as a magnetic or optical disc,incorporating such a software product.

1. A pneumatic assembly for a pressure decay tester of printheadintegrated circuits, the assembly comprising a pressurized air supply; apneumatic clamping arrangement in fluid communication with thepressurized air supply for clamping a carrier for the printheadintegrated circuits such that the carrier is in fluid communication withthe printhead integrated circuits; a valve arrangement to apply apredetermined pressure to the carrier; a sensing arrangement to sense astatic pressure in the carrier; and a control system in communicationwith the clamping, valve and sensing arrangements to control operationthereof and to generate a discernible signal representing said staticpressure such that a decay in said static pressure can be determined. 2.A pneumatic assembly as claimed in claim 1 which the valve arrangementincludes spout clamp valves operatively connected to the control systemto control operation of the spout clamps.
 3. A pneumatic assembly asclaimed in claim 1, in which the pneumatic clamping arrangement includesa support on which the carrier is supported, the clamping arrangementbeing configured so that, when actuated, the carrier is urged againstthe support.
 4. A pneumatic assembly as claimed in claim 3, in which thesupport defines air supply openings in which air inlet spouts of thecarrier are received in use.
 5. A pneumatic assembly as claimed in claim4, in which the clamping arrangement includes pneumatic spout clampspositioned in the support to clamp the spouts in position.
 6. Apneumatic assembly as claimed in claim 4, in which the valve arrangementincludes an air supply isolation valve operatively connected to thecontrol system to isolate the air supply openings from the pressurizedair supply during determination of said static pressure.
 7. A pneumaticassembly as claimed in claim 6, in which the sensing arrangementincludes a pressure transmitter operatively connected to the controlsystem to communicate pressure values upstream of the isolation valve tothe control system.